What is a cat bus?

The Catbus (ネコバス, Nekobasu) is a bus-like creature serving as the second main vehicle for the characters in the anime film My Neighbor Totoro by Studio Ghibli. Appearing in the second half of the film, the Catbus (also commonly known as the Cat Bus or the Nekobus) is a gentle, six-legged feline creature that is covered in fur and has twelve wheels underneath. It is also large enough to hold dozens of passengers inside its body, and can travel very fast. The Catbus is first seen when it speeds past Satsuki and Mei as they are walking home, heading into the forest.